1. Field of the Disclosure
The present disclosure relates to an ozone removal device for removing ozone in an atmosphere, a method for removing ozone, and an image forming apparatus including the ozone removal device.
2. Description of Related Art
Typically, in an electrostatographic printing process of printers, a photoconductive or photoreceptor member is charged by a charging device to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoreceptor member is exposed to selectively dissipate the charges thereon in the irradiated areas. This records an electrostatic latent image on the photoreceptor member. After the electrostatic latent image is recorded on the photoreceptor member, the latent image is developed by bringing a developer material into contact therewith. Generally, the developer material comprises toner particles adhering triboelectrically to carrier granules. The toner particles are attracted from the carrier granules either to a donor roll or to a latent image on the photoreceptor member. The toner attracted to the donor roll is then deposited on latent electrostatic images on a charge retentive surface, which is usually a photoreceptor. The toner powder image is then transferred from the photoreceptor member to a copy substrate.
In order to fix or fuse the toner material onto a support member permanently by heat, it is necessary to elevate the temperature of the toner material to a point at which constituents of the toner material coalesce and become tacky. This action causes the toner to flow, to some extent, onto fibers or pores of the support members or otherwise upon surfaces thereof. Thereafter, as the toner materials cool, solidification of the toner materials occurs causing the toner material to be bonded firmly to the support member.
Electrostatographic printers of the heretofore-mentioned type may employ a number of fluid ionizing discharge devices. Conventional charge/discharge systems utilizing pin/wire scorotrons, corotrons or dicorotrons create ozone which is detrimental to other devices within the document generating system. For example, there may be one at the primary charge station for placing an initial charge of a film belt, and others at additional stations for precleaning the belt, transferring an image to a copy sheet from the belt and detacking the copy sheet from the belt. As is well known, each conventional charge/discharge device produces ions which interact with oxygen in the air to form ozone. As is also well known, ozone presents a serious health hazard to humans. Moreover, ozone can deteriorate machinery and can be especially destructive to photoreceptor elements, such as, film belts employed in electrostatographic machines. During the charging and discharging of a photoreceptor, the corona charging devices generate ozone which is typically measured to 2.0 PPM. Safe ozone levels are typically measured in the 0.1 PPM or less levels.
Attempts at addressing this problem have been made in the prior art in a number of ways. A typical ozone removing device includes either activated carbon or a metal oxide as ozone adsorption agents. Generally, these devices are passive and are placed in the vicinity of ozone producing components to remove any ozone which happens to drift into contact with the devices. In another approach, the ozone absorbing device is placed in proximity to a ventilation exit; however, with this approach, ozone can accumulate in dead air locations since ozone is only removed if entrained in an air ventilation stream. With each of these approaches, the ozone removing devices are relatively large, adding significantly to the size and cost of the device and machine. See, for example, U.S. Pat. No. 5,087,943. Japanese Unexamined Patent Publication No. 42462/1990 [Tokukaihei 2-42462 (published on Feb. 13, 1990)] discloses a technique for heat decomposition of Ozone with a heat source provided in an exhaust duct for exhausting ozone. However, employing a heat source requires raising the temperature to at least 100° C. That is, the temperature of the heat source needs to be raised between 120° C. and 150° C. in order to decompose approximately 50% of ozone while paper is being printed out of the machine. This electricity consumption creates a cost burden because a large amount of electricity is required.
An ozone removal device is shown in U.S. Pat. No. 7,826,763 B2 that combines the use of a honeycomb filter for gas treatment within a machine with an ion emitting unit for emitting negative ions into an atmosphere. A major portion of the ozone gas component is decomposed and absorbed by the filter with the residual ozone gas treatment component being decomposed by the negative ions being generated by the ion emitting unit.
Hence, even with the ozone removing devices disclosed heretofore, there is still a need for a cost effective method and apparatus that reduces the level of ambient ozone which has been emitted from conventional discharge devices.